Abstract WP293: Baseline Perihematomal Edema is Greater in the Presence of a CTA Spot Sign but Does Not Predict Hematoma Expansion Independent of ICH Volume

Abstract

Background: Similarly to intracerebral hemorrhage (ICH), perihematomal edema (PHE) increases with time from onset. A small degree of PHE relative to ICH may suggest a very early timepoint from onset or actively bleeding ICH and therefore predict a higher likelihood of hematoma expansion (HE). The relationship between PHE, ICH and HE has not however been established. Therefore, we aimed to investigate the link between PHE and ICH by time and their relationship with the CTA spot sign and HE. Methods: The PREDICT study was a multicentric, prospective, observational cohort study of ICH patients <6 hours. All study cohort subjects with available baseline CT scan images (n=377) were included in this analysis. Volumes and diameters of total lesion, ICH and PHE were measured systematically by two blinded investigators, respectively. Diameter measurements were taken in the axial CT slice with the largest ICH area. Significant HE was defined as ICH enlargement >33% or >6mL at 24 hours. Results: Correlation between volume and diameter measurements was strong for total lesion (r=0.9; p<0.001) and ICH (r=0.88; p<0.001), but moderate for PHE (r=0.43; p<0.001). PHE represented a half of the total lesion volume at baseline (Table). PHE volume and diameter were not related to time from onset to baseline CT, although PHE/ICH diameter (p=0.017) and volume (p=0.061) ratios were higher the later the baseline CT scan was performed. Spot-sign patients (29.7%) had more baseline PHE, ICH and total lesion than spot-negative patients (Table). HE analysis was limited to 322 patients with follow-up CT before rFVIIa or surgical intervention. HE patients (32%) presented with higher PHE, ICH and total lesion volumes (Table). Baseline PHE diameter and volume ratios however did not predict subsequent HE. Conclusion: Edema represents about half of total lesion volume in acute ICH. Edema and ICH are larger in the presence of a CTA spot sign. Edema alone does not predict subsequent hematoma expansion.